Thermostatic control devices

Abstract

A capsule of a thermic control device contains a substance which expands when heated by an electrical resistor to displace a piston. Devices are disclosed wherein the capsule is disposed transversely in a pipe which carries a circulating fluid, and the front and rear ends of the capsule are sealingly affixed in opposed openings in the wall of the pipe. In one such embodiment, the pipe has two fluid channels; the capsule lies in one channel; and, the piston actuates a valve which is disposed in the other channel.

We claim: 
     
       1. Thermic control device carried by a fluid pipe, said device comprising, a fluid pipe having a flow passage for carrying a circulating fluid, said flow passage having two ends which respectively provide an inlet and an outlet for a circulating fluid which flows through said pipe, said pipe having a sidewall which has a pair of opposed openings formed therein, a hollow capsule forming a chamber which is located between and spaced from the two ends of the pipe, said capsule having a front end provided with a first end wall and a rear end provided with a second end wall, a piston passing through the first end wall of the capsule, said chamber being filled with an expansible substance whose volume varies with the temperature in such a manner as to convert the variation of volume of the expansible substance into an axial displacement of the piston, a thermal means comprising at least one electrical resistor extending in said capsule and in thermal contact with said substance in such a manner as to vary its temperature for the purpose of axially displacing the piston or controlling its displacement relative to said capsule; electrical connecting means extending from said resistor through the second end wall of said capsule, the front and the rear ends of said capsule being sealingly affixed in said opposed openings in the wall of the fluid pipe, said end walls of the capsule facing away from the pipe, said electrical connecting means extending from said capsule to a position which is outside said pipe, said piston projecting from the first end wall of said capsule outside said pipe, said capsule having a section which is located between its front and rear ends and is in thermal contact with the fluid which is circulating in said pipe. 
     
     
       2. A control device according to claim 1 wherein said resistor is a wire resistor. 
     
     
       3. A control device according to claim 1 having two electrically insulated conductor pins which extend sealingly through the second end wall of said capsule, said resistor having ends which are respectively fixed to said pins. 
     
     
       4. A control device according to claim 1 wherein said second end wall of said capsule is a separate part, said resistor being mounted on said separate part, said separate part being joined sealingly to said capsule. 
     
     
       5. A control device according to claim 4 wherein said separate part is a block of insulating material, said electrical conducting means including pins which are sealingly molded in said block of insulating material. 
     
     
       6. A control device according to claim 5 wherein the block of insulating material has a portion projecting inside said capsule, and said resistor is disposed around this projecting portion. 
     
     
       7. Thermic control device carried by a fluid pipe, said device comprising, a pipe having a first fluid circulating channel and a second fluid circulating channel, each of said channels having two ends which respectively provide inlets and outlets for circulating fluids which flow through said pipes, the first channel having a sidewall which has a pair of opposed openings formed therein between the two ends of the first channel, one of said openings extending from the first channel to the second channel, a valve in said second channel, a seat for said valve, a spring biasing said valve in the direction which moves it into its seat, a hollow capsule forming a chamber which has a front end provided with a first end wall and a rear end provided with a second end wall, a piston passing through the first end wall of the capsule, said chamber being filled with an expansible substance whose volume varies with the temperature in such a manner as to convert the variation of volume of the expansible substance into an axial displacement of the piston, a thermal means comprising at least one electrical resistor extending in said capsule and in thermal contact with said substance in such a manner as to vary its temperature for the purpose of axially displacing the piston or controlling its displacement relative to said capsule; electrical connecting means extending from said resistor through the second end wall of said capsule, the front and the rear ends of said capsule being sealingly affixed in said opposed openings in the sidewall of the said first channel, said rear end wall of the capsule facing away from the pipe, said electrical connecting means extending from said capsule to a position which is outside said pipe, said front end of said capsule being exposed to said second channel, said piston projecting outside said first channel and into said second channel, said piston providing control means for said valve and being movable in a direction which lifts the valve off its seat, said capsule having a section which is located between its front and rear ends and is in thermal contact with a fluid which is circulating in said first channel. 
     
     
       8. A control device according to claim 7 wherein said resistor is a wire resistor. 
     
     
       9. A control device according to claim 7 having two electrically insulated conductor pins which extend sealingly through the second end wall of said capsule, said resistor having ends which are resepectively fixed to said pins. 
     
     
       10. A control device according to claim 7 wherein said second end wall of said capsule is a separate part, said resistor being mounted on said separate part, said separate part being joined sealingly to said capsule. 
     
     
       11. A control device according to claim 10 wherein said separate part is a block of insulating material, said electrical conducting means including pins whihc are sealingly molded in said block of insulating material. 
     
     
       12. A control device according to claim 11 wherein the block of insulating material has a portion projecting inside said capsule, and said resistor is disposed around this projecting portion.